In praise of ... the Iraq war march

"I bumped into no end of people coming back from the march, placards under their arms, faces full of self-righteousness, occasional loathing when they spotted me," Alastair Campbell recorded in his diary five years ago today.

The million or so people who marched through London on February 15 2003 did not stop the Iraq war - but they came close, frightening a prime minister who was already past persuading.

After the march, Tony Blair could not paint the invasion as a popular, even moral event: a significant part of the population had demonstrated its outrage. More than any other recent mass protest, the march was a collective national event.

Unlike the Countryside Alliance marches and the poll tax riots, the Iraq march brought together all sorts of people of all sorts of views in the biggest single political protest in British history, a glorious exercise of democratic rights. It included Kate Moss as well as George Galloway, and though the Stop the War coalition that organised it had leftwing roots, many of those who turned out that day did not.

The march also gave the lie to the claim that people no longer cared about politics; not everyone was as detached as Henry Perowne, the wealthy hero of Ian McEwan's novel Saturday, for whom the march was an irritant, disrupting London's traffic. Other cities - in Britain and abroad - held demonstrations too, some bigger. But it was the London march which told the prime minister that if he went to war it would not be in their name - and they were right.